Structured packing for catalytic distillation

ABSTRACT

A catalytic distillation structure that may include a rigid framework having at least two grids with a plurality of horizontal fluid permeable tubes mounted to said grids to form a plurality of fluid pathways among the plurality of horizontal fluid permeable tubes. Additionally, each horizontal fluid permeable tubes may have a profile of a six-sided polygon. Further, the catalytic distillation structure may include a plurality of vertically plates or wires connecting vertically aligned tubes of the plurality of horizontal fluid permeable tubes. Furthermore, the plurality of vertically plates or wires connects from a corner of one vertically aligned tubes to a corner of an adjacent vertically aligned tube.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit under 35 U.S.C. § 119 to U.S. patentapplication Ser. No. 16/381,432, filed on Apr. 11, 2019, which claimsbenefit to U.S. Provisional Patent Application Ser. No. 62/656,219,filed on Apr. 11, 2018, these applications are incorporated by referenceherein in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

Embodiments herein relate generally to a distillation structure that mayperform the dual function of reaction catalyst and mass transfer surfacefor distillation. More particularly, embodiments herein relate to afixed distillation structure which may contain a solid particulatecatalyst. The distillation structure packing provided herein may performthe dual function of providing both catalyst for catalytic reaction andmass transfer surface area for distillation.

Related Art

Catalytic distillation is a branch of reactive distillation whichcombines the processes of distillation and catalysis to selectivelyseparate mixtures within solutions. The main function of catalyticdistillation is to maximize the yield of catalytic organic reactions,such as the refining of gasoline. Additionally, catalysts used forcatalytic distillation are composed of different substances and packedonto varying objects. For example, the different substances may behighly reactive which can significantly speed up the rate of thereaction making them effective catalysts. Typically, the shapes whichthe catalysts are packed to form a geometric arrangement to providespacing in an area (i.e., catalyst bed) in the distillation column wherethe reactant and catalyst come into contact to form the products. Thisspacing is meant to ensure the catalysts are spread within the column.Within the catalytic distillation column, liquid reactants are catalyzedwhile concurrently being heated. As a result, the products immediatelybegin to vaporize and are separated from the initial solution. Bycatalyzing and heating the reactants at the same instant, the newlyformed products are rapidly boiled out of the system.

The concurrent reaction and separation of products from reactants hasbeen practiced for some time, and the advantages have been recognized.Examples of the use of concurrent reaction and distillation aredisclosed in (etherification) U.S. Pat. Nos. 4,232,177; 4,307,254;4,336,407; 4,504,687; 4,918,243; and 4,978,807; (dimerization) U.S. Pat.No. 4,242,530; (hydration) U.S. Pat. No. 4,982,022; (dissociation) U.S.Pat. No. 4,447,668; and (aromatic alkylation) U.S. Pat. Nos. 4,950,834and 5,019,669, as well as other more recent patents assigned toCatalytic Distillation Technologies and/or Lummus Technology, the entireteachings of which are incorporated herein by reference.

Several different catalytic distillation structures have been proposed.See for example U.S. Pat. Nos. 4,302,356 and 4,443,559 in which aparticulate catalyst is contained within the pockets on a cloth beltwound with demister wire to form a catalytic distillation structure andU.S. Pat. No. 4,731,229 which discloses a packing with corrugatedelements and tape to form a catalyst member (the entire teachings ofwhich are incorporated herein by reference). High efficiency packing hasbeen modified to contain catalyst as disclosed in U.S. Pat. Nos.5,073,236 and 5,730,843, the entire teachings of which are incorporatedherein by reference.

U.S. Patent No. 5,730,843 discloses a contact structure comprising arigid frame comprised of at least two substantially vertical duplicategrids, and a plurality of substantially horizontal diamond shape tubesmounted to the grids to form fluid pathways among the tubes.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

In one aspect, the embodiments disclosed herein relate to a catalyticdistillation structure that may include a rigid framework having atleast two grids with a plurality of horizontal fluid permeable tubesmounted to said grids to form a plurality of fluid pathways among theplurality of horizontal fluid permeable tubes. Additionally, eachhorizontal fluid permeable tubes may have a profile of a six-sidedpolygon. Further, the catalytic distillation structure may include aplurality of vertically plates or wires connecting vertically alignedtubes of the plurality of horizontal fluid permeable tubes. Furthermore,the plurality of vertically plates or wires connects from a corner ofone vertically aligned tubes to a corner of an adjacent verticallyaligned tube.

In one aspect, the embodiments disclosed herein relate to a distillationcolumn reactor, for concurrently carrying out reactions and separatingthe products from the reactants, that may include a vertically disposedvessel and one or more catalytic distillation structures disposed in thevertically disposed vessel. Additionally, the catalytic distillationstructure that may include a rigid framework having at least two gridswith a plurality of horizontal fluid permeable tubes mounted to saidgrids to form a plurality of fluid pathways among the plurality ofhorizontal fluid permeable tubes. Each horizontal fluid permeable tubesmay have a profile of a six-sided polygon. Further, the catalyticdistillation structure may include a plurality of vertically plates orwires connecting vertically aligned tubes of the plurality of horizontalfluid permeable tubes. Furthermore, the plurality of vertically platesor wires connects from a corner of one vertically aligned tubes to acorner of an adjacent vertically aligned tube.

It is an advantage of embodiments herein in that greater mobility offluids within the distillation columns can be obtained. It is a furtheradvantage that the catalytic distillation structures according to someembodiments herein may offer better distillation characteristics thanthose structures disclosed in the prior art. Other aspects andadvantages will be apparent from the following description and theappended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a schematic cross section of a packing structureshowing catalyst containing elements and spatial relationship inaccordance with one or more embodiments of the present disclosure.

FIGS. 2A-2H illustrate a schematic cross section of a packing structureshowing catalyst containing elements and spatial relationship inaccordance with one or more embodiments of the present disclosure.

FIG. 3 illustrates an isometric view of the packing structurerepresented by the spatial relationships of FIG. 1.

FIG. 4 illustrates an isometric view of a rigid framework for a packingstructure in accordance with one or more embodiments of the presentdisclosure.

FIG. 5 illustrates a schematic view of a packing structure positioned ina distillation column reactor in accordance with one or more embodimentsof the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described below in detail withreference to the accompanying figures. Like elements in the variousfigures may be denoted by like reference numerals for consistency.Further, in the following detailed description, numerous specificdetails are set forth in order to provide a more thorough understandingof the claimed subject matter. However, it will be apparent to onehaving ordinary skill in the art that the embodiments described may bepracticed without these specific details. In other instances, well-knownfeatures have not been described in detail to avoid unnecessarilycomplicating the description.

In one aspect, embodiments disclosed herein relate to a structurepacking for catalytic distillation. As used herein, the term “coupled”or “coupled to” or “connected” or “connected to” may indicateestablishing either a direct or indirect connection, and is not limitedto either unless expressly referenced as such. Wherever possible, likeor identical reference numerals are used in the figures to identifycommon or the same elements. The figures are not necessarily to scaleand certain features and certain views of the figures may be shownexaggerated in scale for purposes of clarification.

Catalytic distillation structures, according to embodiments herein, areapparatuses that include multiple horizontal fluid permeable tubes,arranged in a grid, may include a liquid transfer connection (e.g.,wire) between vertically adjacent tubes, and the tubes within themultiple grids that are arranged in a certain layout may be containedwithin a frame or frame housing (i.e., rigid framework). The arrangementand shape of the horizontal fluid permeable tubes within the framesignificantly reduces the complexity and design while improving one ormore of the catalyst loading, separation performance, and hydrauliccapacity of the catalytic distillation structure. The horizontal fluidpermeable tubes are mounted throughout the grids to direct and createflow pathways for fluid in the catalytic distillation structure. As usedherein, fluids may refer to liquids, gases, and/or mixtures thereof. Inaddition, plates may be used to connect the horizontal fluid permeabletubes that are vertically aligned within the frame. Furthermore, thevertically aligned tubes connected via plates may include a first seriesthat may be offset adjacently to a second series of vertically alignedtubes connected via the plates.

Conventional catalytic distillation structures typically have tubes withsmall catalyst loading to strengthen the hydraulic capacity of theconventional catalytic distillation structure. Conventional catalyticdistillation structures may include an extensive layout and arrangementof fluid permeable tubes that provide a small area for catalyst loadingwith extensive welds and needing a larger number of fluid permeabletubes. In some instances, the fluid permeable tubes create a turbulentflow path for the fluid traveling within the conventional catalyticdistillation structure and may include complicated bends or changes inorientation. Such conventional catalytic distillation structures may beboth heavier in weight and may also be more expensive to manufacturebecause of the higher number of parts, components, and welds.Accordingly, one or more embodiments in the present disclosure may beused to overcome such challenges as well as provide additionaladvantages over conventional catalytic distillation structures, as willbe apparent to one of ordinary skill.

In contrast to the diamond structure of U.S. Pat. No. 5,730,843,catalytic distillation structures according to embodiments hereininclude shapes and structure that may facilitate superior liquid and/orvapor flow characteristics. Catalytic distillation structures disclosedherein include a contact structure comprising vertical plates. Eachvertical plate includes multiple horizontal fluid permeable tubes. Thevertical connections between each of the fluid permeable tubes mayfacilitate liquid transfer between vertically adjacent horizontal tubes,thereby providing a flow of liquid to maintain the catalyst or disposedwithin each horizontal tube as wetted.

The vertical plates may be spaced adjacent to one another, where thetubes are offset vertically to provide a grid having an efficientpacking of the plates and a tortuous vapor path (open space between theadjacent plates). The vertical connection between the each verticallyadjacent fluid permeable tube may be a solid connection or may be aplurality of wires or fibers interconnecting the tubes. The verticalconnection between the tubes of a single plate should be formed ofmaterial that facilitates fluid communication between the verticallyadjacent tubes, rather than allowing free-fall of liquid from a bottomof a tube, as free-fall of liquid droplets may result in entrainment anddecreased performance attributes of the structure.

The configuration of the tubes may be such that liquid flow is guided tothe catalyst particles contained within the tubes. In some embodiments,the wetting of the catalyst readily occurs due to the liquid traffictraversing down a plate. In other embodiments, wetting of the catalystmay be enhanced or altered by the external shape of the tubes. In yetother embodiments, it has been found that the liquid traffic and vaportraffic may be routed through a highly packed grid, where the shape ofthe tubes allows for enhanced hydraulic capacity, enhanced catalystsloading, and overall improved performance of the structure as comparedto the diamond-shaped tubes of the prior art noted above.

In one or more embodiments, a structured packing of the presentdisclosure may include hexagonal-like tubes mounted along each verticalplates, the plates assembled side-by-side to form a new structurepacking. The hexagonal-like tubes may accommodate more catalyst in thehorizontal fluid permeable tubes to improve catalyst loading withoutcompromising hydraulic capacity as compared with conventional catalyticdistillation structure due, in part, to the horizontal fluid permeabletubes having a profile of a six-sided polygon with plates connectingvertically aligned horizontal fluid permeable tubes. The resultingstructure may have a smooth transition between adjacent horizontal fluidpermeable tubes for a catalytic distillation structure.

Additionally, the catalytic distillation structure may comprisecomponents that are easy to bend into shape (e.g., horizontal fluidpermeable tubes made from flat mesh sheets) thus requiring no to minimalwelding, relaxing control tolerances and improving manufacture (i.e.reduced cost and reduced time to manufacture). Furthermore, thestructured packing for the catalytic distillation structure may needfewer horizontal fluid permeable tubes. Overall the structured packingfor the catalytic distillation structure may minimize productengineering, risk associated with permeable tubes manufacture, reductionof assembly time, hardware cost reduction, weight and envelopereduction. Additionally, the structured packing of the catalyticdistillation structure may have smoother flow paths, improved catalystloading, better separation performance, and increased hydrauliccapacity, with the flexibility of altering a geometry of the six-sidedpolygon horizontal fluid permeable tubes connected via plates. Further,according to embodiments of the present disclosure, the catalyticdistillation structure may be directly connected to a distillationcolumn reactor such as a vertically disposed vessel or similarstructures instead of requiring additional tubes and welds toconcurrently carry out reactions and separating the products from thereactants, thus reducing cost and improving performance of such acatalytic distillation system.

With reference to FIGS. 1-3, embodiments herein include a packingstructure 1 that has a spatial relationship with respect to how aplurality of horizontal fluid permeable tubes 2 are arranged for acatalytic distillation structure. In some embodiments, the plurality ofhorizontal fluid permeable tubes 2 may be vertically aligned in thepacking structure 1. Additionally, it is also envisioned that thevertically aligned tubes 2 may be connected by a plurality of plates orwires 3, facilitating fluid communication between vertically adjacentplates. In addition, the structure includes a plurality of adjacent rowsof said vertically aligned tubes 2. Furthermore, the spatialrelationship of the plurality of horizontal fluid permeable tubes 2creates a tortuous flow path 4. Flow paths, catalyst loading, separationperformance, and hydraulic capacity of a catalytic distillationstructure can be determined by the spatial relationship of the tubes inthe catalytic distillation structure.

Turning to FIG. 1, FIG. 1 illustrates a schematic front view of thepacking structure 1 with the plurality of horizontal fluid permeabletubes 2 having a spatial relationship. One skilled in the art willappreciate that while twelve horizontal fluid permeable tubes 2 areshown, this is just for example purposes and there may be any number ofhorizontal fluid permeable tubes used. The adjacent vertically alignedhorizontal fluid permeable tubes are connected by the plurality ofplates or wires 3 to be a distance h apart from each other. It isfurther envisioned that the plurality of horizontal fluid permeabletubes 2 are shaped to have a profile of a six-sided polygon. Forexample, the six-sided polygon may be a hexagon a having first anglebeta (β) in four corners of the hexagon and a second angle alpha (α) intwo corners of the hexagon. The second angle alpha (α) may be in abottom-most corner and a top-most corner of the hexagon, such that theplurality of plates or wires 3 are connected at the second angle alpha(α) corner of the plurality of horizontal fluid permeable tubes 2. It isfurther envisioned that the first angle beta (β) may be larger than thesecond angle alpha (α). For example, the first angle beta (β) may havethe value of 130° degrees and the second angle alpha (α) may have thevalue of 100° degrees, such that the sum of the interior angles (β, α)equal 720° degrees. While specific values are given, the values of theangles (β, α) are only for examples purposes only and the values of theangles (β, α) may be any values without departing from the scope of thepresent disclosure. Additionally, the hexagon may have sides of whichare different lengths. In some embodiments, the hexagon may include foursides at a first length (a) and two sides at a second length (t).Further, the first length (a) may be longer than the second length (t).The second angle alpha (α) may be in the corner created by the two ofthe sides at the first length. The first angle beta (β) may be in thecorner created by one of the sides at the first length and one of thesides of the second length. Additionally, the two sides at the secondlength (t) may also be parallel to the plurality of plates or wires 3.It is further envisioned that the profile of the plurality of horizontalfluid permeable tubes 2 may be symmetrically along an X-axis and aY-axis.

Still referring to FIG. 1, the horizontal fluid permeable tubes 2 may bealigned to be in vertically adjacent rows (A-E). For example, thevertically adjacent rows (A-E) may be split into a first series (rows A,C, and E) and a second series (rows B and D). The first series (rows A,C, and E) have the plurality of horizontal fluid permeable tubes 2 a, 2c, 2 e to be vertically aligned within the corresponding row and therows A, C, and E may be aligned such that the horizontal fluid permeabletubes 2 a, 2 c, 2 e are horizontally aligned from one row to anotherwithin the first series (rows A, C, and E). Additionally, the secondseries (rows B and D) have the plurality of horizontal fluid permeabletubes 2 b, 2 d to be vertically aligned within the corresponding row andthe rows B and D may be aligned such that the horizontal fluid permeabletubes 2 b, 2 d are horizontally aligned from one row to another withinthe first series(rows B and D). While FIG. 1 illustrates five rows witheither two or three horizontal fluid permeable tubes within the rows,one skilled in the will appreciate how the packing structure 1 is notlimited to five rows with either two or three horizontal fluid permeabletubes and may be any number of rows with any number of horizontal fluidpermeable tubes within the rows.

Further shown by FIG. 1, the packing structure 1 is spatially arrangedsuch that the horizontal fluid permeable tubes 2 a-2 e of adjacent rows(A, C, E with B, D) are offset to allow a portion of the tubes in eachcolumn to overlap but not touch. The overlapping provides the tortuousflow path 4 for fluids, thereby providing more opportunity for contactof the fluids with the tubes of the structure. As described above, theadjacent vertically aligned horizontal fluid permeable tubes areconnected by the plurality of plates or wires 3 to be the distance hapart from each other within each row (A-E). Additionally, the pluralityof plates or wires 3 in one row (A-E) of adjacent vertically alignedhorizontal fluid permeable tubes (2 a-2 e) are spaced a distance d fromthe plurality of plates or wires 3 of an adjacent row (A-E) of adjacentvertically aligned horizontal fluid permeable tubes (2 a-2 e). Thedistance d may be constant for all the plurality of plates or wires 3between rows (A-E) such that the tortuous flow path 4 is the samebetween all the rows (A-E) of adjacent vertically aligned horizontalfluid permeable tubes (2 a-2 e). One skilled in the art will appreciatehow the geometry or dimensions of the horizontal fluid permeable tubes 2and the height h of the plurality of plates or wires 3 manipulate awidth of the flow path 4.

In some embodiments, any number of the plurality of horizontal fluidpermeable tubes (2 a-2 e) may contain a catalyst 30 while other tubes (2a-2 e) may be empty. In some cases, the plurality of horizontal fluidpermeable tubes (2 a-2 e) may all have catalyst 30 or be empty.Additionally, while some of the plurality of horizontal fluid permeabletubes (2 a-2 e) contain the catalyst 30 or are empty, any number of theplurality of horizontal fluid permeable tubes (2 a-2 e) may also includeinerts (not shown) or any combination thereof. Inerts are known in theart to be particles which have little or no participation in reducingthe activation energy of chemical reactions.

In one or more embodiments, a fraction of open area for vapor and liquidflow at a tightest constriction in the packing structure 1 is given bythe dimensions of the horizontal fluid permeable tubes (2 a-2 e) and thetortuous flow path 4. For example, at the highest catalyst density for agiven inter plate distance d, a width w of the tortuous flow path 4 maybe substantially constant. It is further envisioned that if lowercatalyst densities are desired, the spacing of vertically alignedhorizontal fluid permeable tubes (2 a-2 e) is increased (i.e., theheight h of the plurality of plates or wires 3 is increased).Consequently, the width w of the tortuous flow path 4 is varied suchthat the plurality of horizontal fluid permeable tubes (2 a-2 e) arefurther apart from each other while still being at the distance d fromthe plurality of plates or wires 3. Alternatively, catalyst density maybe reduced by the inert packing or empty tubes. Thus, by combinations ofstructural configuration and tube loading in the packing structure 1provide a highly adaptable means to contact fluids of great diversity.

One skilled in the art will appreciate how the packing structure 1, asillustrated in FIG. 1, minimizes a hydraulic load on the catalyticdistillation structure required to maintain good liquid-catalystcontacting and provides very short contact time between the liquid andcatalyst before vapor-liquid exchange occurs. Maintaining goodliquid-catalyst contacting and providing very short contact time betweenthe liquid and catalyst before vapor-liquid exchange occurs may providea more efficient utilization for the catalyst over a range of hydraulicloadings below a flood point and over a wide range of operatingconditions such as reflux ratio. Additionally, the packing structure 1may also have a low height equivalent to a theoretical plate (HETP) inorder to provide greater driving force for equilibrium limited systems.

In a catalytic distillation use, there will be both a liquid and a vaporphase. In some embodiments, the liquid will contact the plurality ofhorizontal fluid permeable tubes 2 and form a film. Additionally, theliquids will be absorbed to an extent into the plurality of horizontalfluid permeable tubes 2 by adsorption onto the catalyst 30 or otherfiller in the plurality of horizontal fluid permeable tubes 2. Althoughthe packing structure 1 serves as a distillation structure, the presenceof the particulate material in the plurality of horizontal fluidpermeable tubes 2, and the capillary attraction of the liquid theretowill provide a different environment from conventional methods. Inconventional methods, the liquid as well as the gas follow the path ofleast resistance through the pathways. However, with portions of theliquid in the column being handled by the tubes, there is lesscompetition for the low resistance open pathways, thus producing a lowerback pressure than would be expected in conventional methods.

With reference to FIGS. 2A-2H, with respect to FIG. 1, FIGS. 2A-2Hillustrate alternative spatial relationships within the packingstructure 1 as well as alternative geometries of the tubes.Specifically, FIGS. 2A-2H illustrate the profile of alternativegeometries and spatial relationships of the plurality of horizontalfluid permeable tubes 2 to create the tortuous flow path 4 for fluidswithin the packing structure 1. FIG. 2A shows the plurality ofhorizontal fluid permeable tubes 2 are shaped to have the profile of afive-sided polygon (i.e., pentagon). For example, the tubes 2 may have atop surface 17 perpendicular to the plates or wires 3, two side surfaces18 parallel to the plates or wires 3, and two angled surfaces 19 suchthat two angled surfaces 19 create a point 20. Additionally, the platesor wires 3 may connect vertically aligned tubes 2 from the top surface17 of one tube to the point 20 of a vertically adjacent tube.

FIG. 2B shows the plurality of horizontal fluid permeable tubes 2 areshaped to have the profile of a cylinder. For example, the tubes 2 mayhave two side surfaces 21 parallel to the plates or wires 3 and twocurved surfaces 22 connected in between the two side surfaces 21.Additionally, the plates or wires 3 may connect vertically aligned tubes2 from the curved surfaces 22 of one tube to the curved surfaces 22 of avertically adjacent tube.

FIG. 2C shows the plurality of horizontal fluid permeable tubes 2 areshaped to have the profile of a round polygon. For example, the roundpolygon may be a circle, oval, or an ellipse. Additionally, the platesor wires 3 may connect vertically aligned tubes 2 from a tangent pointof one tube to a tangent point of a vertically adjacent tube.

FIG. 2D shows the plurality of horizontal fluid permeable tubes 2 areshaped to have the profile of a four-sided polygon (i.e., square ordiamond). A non-limiting example of the spatial relationship of FIG. 2Dis described in U.S. Pat. No. 5,730,843, the entire teachings of whichare incorporated herein by reference. Additionally, the plates or wires3 may connect vertically aligned tubes 2 from a top corner 23 of onetube to a bottom 24 corner of a vertically adjacent tube.

FIG. 2E shows the plurality of horizontal fluid permeable tubes 2 areshaped to have the profile of a pie shape. For example, the tubes 2 mayhave one rounded surface 25 and two linear surfaces 26. The two linearsurfaces 26 each have a first end 27 connected to the one roundedsurface 25 and a second end connected together to create a point 28below the first ends 27. Additionally, the plates or wires 3 may connectvertically aligned tubes 2 from the rounded surface 25 of one tube tothe point 28 of a vertically adjacent tube.

FIG. 2F shows the plurality of horizontal fluid permeable tubes 2 areshaped to have the profile of a heart shape. For example, the tubes 2may have two rounded surfaces 29 to be symmetrical or symmetrical andconnect at a top point 31 and a bottom point 32 to create a heart shape.It is further envisioned that the two rounded surfaces 29 may be in factlinear to create a more square-type heart. Additionally, the plates orwires 3 may connect vertically aligned tubes 2 from the top point 31 ofone tube to the bottom point 32 of a vertically adjacent tube.

FIG. 2G shows the plurality of horizontal fluid permeable tubes 2 areshaped to have the profile of an arrow or spear. For example, the tubes2 may be a downward facing arrow (as shown in FIG. 2G) or an upwardfacing arrow (not shown). Additionally, the plates or wires 3 mayconnect vertically aligned tubes 2 from a tip of one tube to an internalcorner 34 of a vertically adjacent tube.

FIG. 2H shows the plurality of horizontal fluid permeable tubes 2 areshaped to have the profile of a shape of a teardrop likeness. Forexample, the teardrop is rounded all around with a single tangent pointbeing a corner node 35. Additionally, the plates or wires 3 may connectvertically aligned tubes 2 from the corner node 35 of one tube to atangent point of a vertically adjacent tube. It is further envisionedthat, with reference to FIGS. 1-2H, that the profile of the plurality ofhorizontal fluid permeable tubes 2 is not limited to just one profilefor all the tubes 2 within the respective packing structure 1. Oneskilled in the art will appreciate how the profiles described in FIGS.1-2H may be used in conjunction with one another to have a packingstructure including a plurality of tubes with different profiles withoutdeparting from the scope of the present disclosure.

In some embodiments, with reference to FIGS. 1-2H, one or more tubes 2may be removed to leave an open space (not shown). The open space mayallow for the connection of transverse pathways and provide at least astortuous pathway for gases, such as an intersticial pathway. The flow ofthe gases is shown by the upward facing carets (e.g., gases flowingupward). Additionally, liquids may flow over and through the tubes 2 andmaterial therein as shown by the downward facing carets (e.g., liquidsflowing downward). The amount of carets is shown for examples purposesonly and the liquid and gas flow paths may flow outside the caretswithout departing from the present disclosure. Further, the liquids mayflow over and through the plates or wires 3. As the tubes 2 may containthe catalytic material 30 in particulate form, it is further envisionedthat the ends of each tube 2 containing particulate catalytic materialmay be sealed, for example by crimping, inserted end caps, or welding.Additionally, some of the tubes 2 may be void of any particulatematerial and/or contain inert particulate material. For example, thevoid packings may be less dense and provide excellent distillationcharacteristics with a great deal of open space and surfaces. The inertelements are the packings filled with inert particulate material thatmay be the same size, smaller or larger than the catalytic particulatematerial. In some cases, the inert elements allow for all of the samehydraulic characteristics of the catalytic elements but may also reducethe catalytic reactions, which in catalytic distillation also designatedreactive distillation that is frequently a reversible reaction. Anon-limiting example of reactive distillation is described in U.S. Pat.No. 5,019,669, the entire teachings of which are incorporated herein byreference. Hence, by diluting the reactive elements but maintaining thedistillation elements, a higher degree of the separation aspect of thecatalytic distillation may be obtainable. In other words, by dispersingthe inert elements between the catalytic elements in a given packingstructure, the fractional separation is emphasized; while in a system(see FIG. 5) as a whole comprising a column with a plurality of thecatalytic packing structures, the force of the reaction is maintained.

Referring to FIG. 3, the plurality of horizontal fluid permeable tubes 2of the packing structure 1, as shown in FIG. 1, is illustrated in anisometric view without showing a rigid framework (see FIG. 4) in whichthe packing structure 1 may be installed. While FIG. 3 shows theplurality of horizontal fluid permeable tubes 2 having the profiledescribed in FIG. 1, the profile may be any profile described in FIGS.1-2H (FIGS. 2A-2H are not shown in an isometric view for simplicitypurposes only). Each of the plurality of horizontal fluid permeabletubes 2 may have an opening 5 at a first end 6 of said tubes 2. It isfurther envisioned that said tubes 2 may have a second opening (notshown) at second end (not shown) opposite of the first end 6.Additionally, said tubes 2 extend horizontally in a horizontal plane Pto be a length. Further shown by FIG. 3, the plurality of plates orwires 3 may also extend horizontally in the horizontal plane P to be inunison with the plurality of horizontal fluid permeable tubes 2.Furthermore, the plurality of horizontal fluid permeable tubes 2 areshown to be in adjacent rows (as described in FIG. 1) to be verticallyaligned and connected by the plurality of plates or wires 3 within theadjacent rows. In some embodiments, the adjacent rows may be aligned tobe side by side at the distance d (as described in FIG. 1). While FIG. 3illustrates twenty adjacent rows, the present disclosure is not limitedto twenty vertically aligned rows and may have one or more verticallyaligned rows. It is further envisioned that the horizontal fluidpermeable tubes 2 may be made from a group of material selected from awire mesh material, any permeable material, or a combination thereof.Furthermore, the wire mesh material may be selected from a metal, carbonfiber, plastic, glass, or composite. It is further envisioned that thehorizontal fluid permeable tubes 2 may have only a portion made fromwire mesh and another portion made from a non-permeable material.Additionally, the plurality of plates or wires 3 may also be made fromthe wire mesh material, any permeable material, or non-permeablematerial.

The horizontal permeable tubes 2 of FIGS. 1-3 are illustrated with aparticular orientation of the cross-sectional shape of the tube. Forexample, the teardrop shape of FIG. 2H is illustrated with the angledend of the teardrop facing upward and the rounded portion of theteardrop oriented downward. Embodiments herein also contemplateinversion of the tube shapes disclosed. For example, a tube may have ateardrop shape, with the angled end of the teardrop facing downward andthe rounded portion of the teardrop oriented upward.

Further, although the packing structures of FIGS. 1-3 are illustratedwith a vertical orientation, it is contemplated herein that the packingstructure may be disposed at an angle relative to vertical. In otherwords, the orientation of the structure may result in an upward, butangled relative to vertical, vapor pathway 4, and the plates or wires 3may provide a downward, but angled relative to vertical, liquid pathwaybetween tubes 2. Additionally, consecutive vertical sections of thepacking structure within a distillation column may be oriented atopposing angles, resulting in a zig-zag pattern for vapor and liquidtraffic within the column.

FIG. 4, in one or more embodiments, shows a rigid framework 7 in whichthe packing structure (1 as described in FIGS. 1-3) may be installed oraffixed. The rigid framework 7 may include at least two grids 8A, 8Bwhich are spaced apart by one or more support rods 9. Additionally, thesupport rods 9 are each secured to both grids 8A, 8B, for example bywelding, crimping, mechanical fasteners or coupled to be fixed orremovable attached. The support rods 9 extend horizontally in thehorizontal plane P (same as FIG. 3) to be a length. It is furtherenvisioned that the securing of the grids 8A, 8B together may furtherinclude the use of threaded rods and nuts or bolts (not shown).Furthermore, the grids 8A, 8B may have a plurality of openings 10. Insome embodiments, the support rods 9 may be affixed in the plurality ofopenings 10. The resulting structure of FIG. 4 is a rigid and capableframe supporting at least one other structure of the present invention,and loads of 100 to 200 pounds. The rigid framework 7 may be made of amaterial selected from a metal, carbon fiber, plastic, composite, or anyload bearing material.

As described, the packing structure (1) may be installed or affixed tothe rigid framework 7. The plurality of horizontal fluid permeable tubes(2) may be mounted to the grids 8A, 8B. For example, the first end (6)of said tubes (2) may be welded, crimped, or coupled to be fixed orremovable attached to a first grid 8A, and in addition, the second endof said tubes (2) may be welded, crimped, or coupled to be fixed orremovable attached to a second grid 8B. Additionally, the support rods 9and the tubes (2) may have a similar length to equally space apart thegrids 8A, 8B. Further, the plurality of plates (3) may also be welded,crimped, or coupled to be fixed or removable attached to the grids 8A,8B. It is further envisioned that the tubes (2) may be positioned in therigid framework 7 such that the openings of the tubes (2) are alignedwith the openings 10 of the grids 8A, 8B. In some embodiments, theopenings 10 are approximately the same size and configuration as thegeometry of the tubes (2), such that the tubes (2) are held fast andbind in the openings 10 when the grids 8A, 8B are secured together bythe support rods 9.

Referring to FIG. 5, in one or more embodiments, FIG. 5 shows one ormore catalytic distillation structure(s) 11 positioned in a distillationcolumn reactor 12. The catalytic distillation structures 11 may includethe packing structure (1) with the plurality of horizontal fluidpermeable tubes (2) and the rigid framework (7) as described in FIGS.1-4. Additionally, the catalytic distillation structure(s) 11 may befixed or removable attached to the distillation column reactor 12 bywelding, crimping, adhesives, or mechanical fasteners known in the art.Additionally the catalytic distillation structure(s) 11 may be supportedin the distillation column reactor 12 in any efficient manner. Forexample, the catalytic distillation structure(s) 11 may be supported andseparated by inert distillation packing (not shown) such as Rashig ringsor the like. Further shown by FIG. 5, the distillation column reactor 12may have one or more re-boilers 13, condensers 14, and feeding tanks 15attached therein to the distillation column reactor 12 via flow lines(represented by arrows). In some embodiments, the re-boilers 13 may haveone or more separators 16 attached therein via the flow lines.

While FIG. 5 shows only one catalytic distillation structure 11 in thedistillation column reactor 12, one skilled in the art will appreciatehow the present disclose is not limited to just one catalyticdistillation structure 11 and may have additional catalytic distillationstructures without departing from the scope of the present disclose.Additionally, the multiple catalytic distillation structures 11 may havesame or different packing structures (configurations described in FIGS.1-2H). It will further be appreciated that more than one catalyticdistillation structures 11 may be placed in the distillation columnreactor 12 at various heights. In some embodiments, that multiplecatalytic distillation structures 11 may be arrayed vertically andlaterally in the distillation column reactor 12. Furthermore, the flowline from the feeding tank 15 to the distillation column reactor 12 isshown to be above the catalytic distillation structure 11 in thedistillation column reactor 12; however, the present disclosure is notlimited to such an arrangement, as the flow lines may be above, below,at, or in between the catalytic distillation structures 11. One skilledin the art will appreciate how the distillation column reactor 12 may beattached to other distillation column reactors. It is further envisionedthat a dilution of a volume of catalyst present in the distillationcolumn reactor 12 may be insignificant given the dynamic nature ofcatalytic distillation and the improved distillation characteristicsdescribed above. In some cases, the volume of the catalyst loaded intothe wire mesh will depend upon its reaction to swelling.

As described above with respect to FIGS. 1 and 3, FIG. 3 illustrates a3D schematic of a structure including hexagon-like tubes, and FIG. 1shows a schematic cross-section of the structure. The hexagonal-liketubes are made of materials permeable to fluid (liquids and/or gases),preferentially wire mesh. All or at least a portion of hexagonal-liketubes can accommodate a catalyst material, promoting catalytic reactionson structure packing. On the other hand, all the surfaces of verticalplates including hexagonal-like tube surfaces along with accommodatedcatalyst surfaces may facilitate mass transfer and interaction betweenvapor and liquid phases for a distillation process. As shown in thefigures, the vertical plates are assembled to stack togetherside-by-side to allow the hexagonal-like tubes of adjacent plates offsetwithout touch to form a pathway (4 shown in FIG. 1) for fluids. Eachhexagonal-like tube usually is used to accommodate catalyst but notnecessarily all tubes need contain catalyst. The dimension of eachhexagonal-like tube usually is same and the shape is symmetric along twoaxes, vertical and horizontal. And, the lengths of sides (e.g., a and t)and the angles such as α and β can be adjusted to manipulate the size ofa hexagonal-like tube to control the catalyst loading in a structurepacking. The number of hexagonal-like tubes per a certain height alongeach plate, the length (h) of connection line between adjacent tubesalong each plate and the distance (d) between adjacent plates can beadjusted as well as the size of a hexagonal-like tube to manipulate thewidth of the flow pathway (4), which may influence or controlhydrodynamic performance or hydraulic capacity of a structure packing.As compared to the structure packing reported in U.S. Pat. No.5,730,843, embodiments herein possess one or more of the followingadvantages:

-   -   Each hexagonal-like tube may accommodate more catalyst than a        diamond tube, which may improve catalyst loading for a specific        volume of structure packing without compromising hydraulic        capacity or hydrodynamic performance.    -   A hexagonal-like tube has a smoother transition between adjacent        sides than a diamond tube. It means that hexagonal-like tubes        are relatively easy to bend from flat mesh sheet, facilitating        manufacturing process of this structure packing. It also results        in a much smoother transition for fluids to travel along flow        pathways during a catalytic distillation process, improving        hydraulic capacity of the structure packing.    -   The hexagonal tubes herein may provide an increased mass loading        per unit volume relative to the diamond shaped tubes of U.S.        Pat. No. 5,730,843. In some embodiments, the increase in mass        loading per unit volume will be in the range from 10% to 50%.        Further, the increase in loading (mass per unit volume) can be        achieved without significant hydrodynamic impact.    -   The structure packing may be more cost effective, potentially        requiring fewer plates and fewer welds while still achieving the        same performance.    -   The new structure packing design possesses flexibility to        achieve desired catalytic distillation performance by varying        dimensions of a hexagonal-like tube and arrangement of        hexagonal-like tubes along each plate in terms of catalyst        loading, separation performance and hydraulic capacity.    -   In the present hexagonal design, the lengths of sides a and t,        and the angles β and α, can be adjusted to manipulate the size        of a hexagonal-like tube.

In summary, embodiments herein are directed toward a new structurepacking specifically useful for reactive or catalytic distillationprocesses. However, the new structure may be generally used forliquid/liquid, gas/liquid or gas/gas concurrent or countercurrent flowin the presence of a catalyst material.

While the present disclosure has been described with respect to alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that other embodiments may bedevised which do not depart from the scope of the disclosure asdescribed herein. Accordingly, the scope of the disclosure should belimited only by the attached claims.

What is claimed:
 1. A catalytic distillation structure, comprising: arigid framework having at least two grids spaced apart; a plurality offluid permeable tubes mounted to said grids to form a plurality of fluidpathways among the plurality of fluid permeable tubes, wherein eachfluid permeable tubes have a profile of a six-sided polygon, whereineach of the fluid permeable tubes extend from a first to a second of theat least two grids; a plurality of plates or wires connecting andaligning tubes of the plurality of fluid permeable tubes, wherein theplurality of plates or wires connects from a lowermost corner of onealigned tubes to an uppermost corner of an adjacent aligned tube.
 2. Thecatalytic distillation structure of claim 1, further comprising a firstseries of vertically aligned tubes and a second series of verticallyaligned tubes, wherein the first series comprises the plurality of fluidpermeable tubes arrayed in a parallel, adjacent and aligned columnswithin the first series, and the second series comprises the pluralityof fluid permeable tubes arrayed in a parallel, adjacent and alignedcolumns within the second series.
 3. The catalytic distillationstructure of claim 2, wherein the first series of aligned tubes areoffset from the second series of aligned tubes and the fluid permeabletubes of the first series overlap the fluid permeable tubes of thesecond series without contacting the fluid permeable tubes of the secondseries of plates to thereby form a tortuous fluid pathway.
 4. Thecatalytic distillation structure of claim 3, wherein a height of theplurality of plates or wires evenly space apart the fluid permeabletubes in the first series and the second series.
 5. The catalyticdistillation structure of claim 4, wherein the first series and thesecond series are stacked side-by-side a distance apart.
 6. Thecatalytic distillation structure of claim 3, further comprising ageometry of the six-sided polygon forming a first angle in four cornersof the six-sided polygon, a second angle in two corners of the six-sidedpolygon, wherein the first angle is greater than the second angle. 7.The catalytic distillation structure of claim 6, wherein the secondangle is in the corners of vertically aligned tubes that are connectedby the plurality of plates or wires.
 8. The catalytic distillationstructure of claim 7, wherein the six-sided polygon comprises two sidesof a first length and four sides of a second length.
 9. The catalyticdistillation structure of claim 8, wherein the first angle is at acorner of a connection of a side of the first length and a side of thesecond length and the second angle is at a corner of a connection of twosides of the second length.
 10. The catalytic distillation structure ofclaim 9, wherein the second length is greater than the first length. 11.The catalytic distillation structure of claim 9, wherein the secondlength is shorter than the first length.
 12. The catalytic distillationstructure of claim 1, wherein the plurality of fluid permeable tubes andplurality of plates or wires are made of a same material.
 13. Thecatalytic distillation structure of claim 1, further comprising at leastone support rod to rigidly hold the at least two grids a distance apartfrom each other.
 14. The catalytic distillation structure of claim 1,wherein each of the plurality of fluid permeable tubes have an openingat a first end and second end of said tubes.
 15. The catalyticdistillation structure of claim 1, wherein the grids comprises aplurality of openings, wherein the plurality of openings of the gridshave a profile equal to the profile of the plurality of fluid permeabletubes.
 16. The catalytic distillation structure of claim 1, wherein aseries of aligned tubes connected via the plates or wires do notcomprise welds.
 17. The catalytic distillation structure of claim 16,wherein the plurality of fluid permeable tubes are positioned in theplurality of openings of the grids.
 18. The catalytic distillationstructure of claim 1, wherein the tubes are horizontal and are alignedvertically.
 19. A distillation column reactor for concurrently carryingout reactions and separating the products from the reactants,comprising: a vertically disposed vessel; and one or more catalyticdistillation structures as recited in claim 1 disposed in the verticallydisposed vessel.
 20. The distillation column reactor of claim 19,wherein the rigid framework is removably attached to the verticallydisposed vessel by welding, crimping, adhesives, or mechanicalfasteners.